Light emitting device

ABSTRACT

A light emitting device includes a substrate, a light emitting element, an additional light emitting element, a light reflecting resin member, an electrically conductive wire, an additional electrically conductive wire, and a sealing member. The substrate is provided with a conductor wiring. The light emitting element is mounted on the substrate. The electrically conductive wire electrically connects the conductor wiring and the light emitting element with at least a part of the electrically conductive wire being embedded in the light reflecting resin member. The additional electrically conductive wire electrically connects the light emitting element and the additional light emitting element, with the additional electrically conductive wire not being in contact with the light reflecting resin member. The sealing member is disposed in a region surrounded by the light reflecting resin member to cover the light emitting element.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 12/341,189 filed on Dec. 22, 2008. This application claimspriority to Japanese Application No. 2007-339127 filed in Japan on Dec.28, 2007, and Japanese Application No. 2008-22815 filed in Japan on Feb.1, 2008. The entire disclosures of U.S. patent application Ser. No.12/341,189, and Japanese Application Nos. 2007-339127 and 2008-22815 areincorporated hereinto by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a light emitting device that can beused in an indicator, a lighting apparatus, a display, a backlight forliquid crystal display etc., and more particularly to a light emittingdevice excellent in light extraction efficiency in which highreliability can be obtained even when a semiconductor light emittingdevice having high output is mounted.

2. Background Information

In recent years, various light emitting devices using a semiconductorlight emitting element (hereinafter, may be referred to as a lightemitting element) have been developed, and methods to improve outputhave been explored.

For example, JP2004-265979A describes provision of reflector as close aspossible to the light emitting element between a light emitting elementand a wiring land provided on a substrate to obtain a high luminance.

However, in a case where such a reflector is provided, in order toprevent a light emitting element and a conductive wire from beingdamaged, a certain distance is required between such electroniccomponents and the reflector. Thus, downsizing is difficult and the sizeof the light emitting device is limited. Further, the light emittingelement and the reflector are set apart, which may cause a reduction ofthe light extracting efficiency. Particularly, in a case where a goldwire is used to electrically connect a light emitting element to eachterminal, gold absorbs light from the light emitting element and alonger wire is required when the reflector is provided as describedabove. Thus, the absorption of light increases and the output of lightdecreases.

In addition, a light emitting diode which is a light emitting element isdipolar element. Therefore, an insulating portion is needed between thepositive and negative wiring lands (conductor wiring) provided on thesubstrate. Typically, the insulating portion can be easily provided byexposing an insulating substrate material of the substrate, or the like.However, various limitations are set on an insulating substrate materialso as to produce packages efficiently or to secure mechanical strength,or the like. Therefore a material having a desired optical properties(optical reflectivity and optical absorptance) has not always been used.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a light emittingdevice includes a substrate, a light emitting element, an additionallight emitting element, a light reflecting resin member, an electricallyconductive wire, an additional electrically conductive wire, and asealing member. The substrate is provided with a conductor wiring. Thelight emitting element is mounted on the substrate. The light reflectingresin member is configured and arranged to reflect light emitted fromthe light emitting element. The electrically conductive wireelectrically connects the conductor wiring and the light emittingelement with at least a part of the electrically conductive wire beingembedded in the light reflecting resin member. The additionalelectrically conductive wire electrically connects the light emittingelement and the additional light emitting element, with the additionalelectrically conductive wire not being in contact with the lightreflecting resin member. The sealing member is disposed in a regionsurrounded by the light reflecting resin member to cover the lightemitting element.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view illustrating an example of a lightemitting device according to the present invention.

FIG. 1B is a partially sectional perspective view of a section takenalong line X-X′ of FIG. 1A of a light emitting device.

FIG. 1C is a top plan view of a light emitting device of FIG. 1A.

FIG. 2 is a perspective view illustrating an example of a light emittingdevice according to the present invention.

FIG. 3 is a partially sectional perspective view illustrating an exampleof a light emitting device according to the present invention.

FIG. 4 is a perspective view illustrating an example of a light emittingdevice according to the present invention.

FIG. 4B is a sectional view of a section taken along line Y-Y′ of FIG.4A of a light emitting device.

FIG. 4C is a sectional view of a section taken along line Z-Z′ of FIG.4A of a light emitting device.

FIG. 5 is a perspective view illustrating another example of a lightemitting device taken along line Z-Z′ of FIG. 4A.

FIG. 6 is a sectional view illustrating an example of a light emittingdevice according to the present invention.

FIG. 7 is a top plan view illustrating an example of a light emittingdevice according to the present invention.

FIG. 8 is a top plan view illustrating an example of a light emittingdevice according to the present invention.

FIG. 9A is a perspective view showing a part of light emitting deviceaggregation prior to dividing the substrate, illustrating a state beforedisposing a light reflecting resin.

FIG. 9B is a perspective view showing a part of light emitting deviceaggregation prior to dividing the substrate, illustrating a state afterdisposing a light reflecting resin to the state shown in FIG. 9A.

FIG. 10A is a perspective view illustrating a method of manufacturing alight emitting device according to the present invention.

FIG. 10B is a perspective view illustrating a method of manufacturing alight emitting device according to the present invention.

FIG. 10C is a perspective view illustrating a method of manufacturing alight emitting device according to the present invention.

FIG. 10D is a perspective view illustrating a method of manufacturing alight emitting device according to the present invention.

FIG. 10E is a perspective view illustrating a method of manufacturing alight emitting device according to the present invention.

FIG. 11A is a perspective view illustrating an example of a lightemitting device according to the present invention.

FIG. 11B is a sectional view of a light emitting device taken along lineY-Y′ of FIG. 11A.

FIG. 11C is a top plan view of the light emitting device of FIG. 11Aillustrating a sealing member in its transparent state.

FIG. 12 is a top plan view illustrating an example of a light emittingdevice according to the present invention.

FIG. 13A is a perspective view illustrating a method of manufacturing alight emitting device according to the present invention.

FIG. 13B is a perspective view illustrating a method of manufacturing alight emitting device according to the present invention.

FIG. 14 is a perspective view illustrating a method of manufacturing alight emitting device according to the present invention.

FIG. 15 is a perspective view illustrating a method of manufacturing alight emitting device according to the present invention.

FIG. 16A is a perspective view showing a nozzle of a resin dischargingapparatus.

FIG. 16B is a perspective view showing a nozzle of a resin dischargingapparatus.

FIG. 16C is a perspective view showing a nozzle of a resin dischargingapparatus.

FIG. 17A is a perspective view illustrating a method of manufacturing alight emitting device according to the present invention.

FIG. 17B is a sectional view illustrating a method of manufacturing alight emitting device according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention will be describedbelow with reference to the accompanying drawings. Herein, the form ofthe following embodiments are intended as examples of a light emittingdevice that are representative of the technology behind the presentinvention, and any limitation of the scope of the invention by theembodiments is not intended.

In addition, the present specification will by no means limit themembers described in claims to the members described in the embodiments.Especially, size, material, shape, and the relative configuration etc.of the components described in the preferred embodiments are forillustration, and do not intend to limit the invention therein, unlessspecifically described. In the drawings, the size and the positionalrelationship of the components may be exaggerated for clarity. Further,in the description below, identical members or members of the samequality are assigned the same names and reference numerals and detaileddescription thereof will be arbitrarily omitted. In each constitutingcomponent of the present invention, multiple components may beconstructed using the same member so that one member can serve asmultiple components, or vice versa, a function of a member may be sharedby multiple members.

FIG. 1A is a perspective view showing a light emitting device 100 of thepresent embodiment, FIG. 1B is a partially sectional perspective view ofa section taken along line X-X′ of FIG. 1A, and FIG. 1C shows a top planview of FIG. 1A. In the present embodiment, a light emitting device 100includes an approximately rectangular substrate 101 having conductorwirings 103A, 103B, and 103C provided on its top surface, and aplurality of light emitting elements 104 mounted on the conductor wiring103A. A surrounding of these light emitting elements 104 is providedwith a light reflecting resin 102 (light reflecting resin member) whichreflects light from the light emitting elements, and electricallyconductive wires 105 which electrically connect the conductor wiring103A, 103B and the light emitting elements 104. The conductor wiring103C is made of the same material as the conductor wiring 103A, 103Beach of which serves as an electrode, but the conductor wiring 103C isprovided as a mark (cathode mark/anode mark) for indicating the polarityof the light emitting device and is not for electrical connection.

According to the present invention, at least a part of the electricallyconductive wires 105 is buried in the light reflecting resin 102. Withthis arrangement, exposed area of the electrically conductive wires 105can be minimized so that the absorption of light can be reduced, andthus, optical output can be improved.

Light Reflecting Resin

In the present embodiment, the light reflecting resin 102 is configuredand arranged to reflect light from the light emitting elements 104 andprovided to surround the light emitting elements. The light reflectingresin 102 also covers at least a part of the electrically conductivewires 105. With this arrangement, absorption of light by theelectrically conductive wires can be reduced and light can be extractedefficiently.

The electrically conductive wires 105 are arranged such that, as shownin FIG. 1B, one of the electrically conductive wires 105 connected fromthe light emitting elements 104 is connected to the conductor wiring103A and the other is connected to the conductor wiring 103B. Theconductor wiring 103A is formed such that the region where the lightemitting elements 104 to be mounted and the region to which theelectrically conductive wires 105 are attached are connected at aportion buried in the light reflecting resin 102 (not shown). Then, eachpart of the electrically conductive wires 105 connected to the conductorwirings 103A, 103B are buried in the light reflecting resin 102. Suchstructure can be obtained by disposing the light reflecting resin 102after connecting the electrically conductive wires 105 to the conductorwiring 103A, 103B, respectively.

Here, the light reflecting resin 102 is provided to cover the connectingportion between the electrically conductive wires 105 and the conductorwirings 103A, 103B, but the provision is not limited thereto, forexample, the light reflecting resin 102 may be provided between theconnecting portion and the light emitting elements to cover theelectrically conductive wires being in the regions other than theconnecting portion.

Also, there is no need to bury all the electrically conductive wiresbeing used, and for example as shown in FIG. 1A, among a plurality ofthe electrically conductive wires, only the electrically conductivewires directly connected to the conductor wiring may be buried.

Also, in the present embodiment, at least a part of the substrateexposed from the conductor wiring, that is, the substrate which isexposed without provided with a conductor wiring (hereinafter referredto as an “exposed region”), is buried in the light reflecting resin.

For example as shown in FIG. 1B, light transmitted and/or absorbed atthe substrate 101 can be reduced by using the light reflecting resin 102covering the exposed region 101A of the substrate exposed, such asbetween the conductor wiring 103A whereon the light emitting elementsare mounted and the conductor wiring 103B to which the electricallyconductive wires are connected. Typically an insulating member such asceramic is used for the material of the substrate in view of mechanicalstrength and workability, but with this arrangement, light from thelight emitting element may be transmitted through an exposed region ofthe substrate where a conductor wiring is not provided. The substrate isnot disposed on a side toward which light is intended to be emitted,that is, the substrate is disposed on a side opposite from an upwarddirection such as shown in FIG. 1A with respect to the light emittingelements. Therefore, it is undesirable if light transmits toward thesubstrate because it causes a loss in the amount of light in a desireddirection and results in reduction of light extraction efficiency.

According to the present invention, a material having at least a loweroptical transmittance than that of the substrate and a higherreflectivity on the light from the light emitting elements is selectedfor the light reflecting resin, and an exposed region of the substrateis buried (covered) with the light reflecting resin. Thus, a loss oflight due to transmittance of light in an undesired direction can bereduced. Also, in a case where a substrate capable of absorbing lightsuch as a ceramic of darker color is used, absorption of light by thesubstrate can be reduced by covering, that is, by burying the exposedregion of the substrate with a light reflecting resin. As a result,light extracting efficiency can be improved.

In a case where the exposed region as described above is buried in alight reflecting resin, such an advantageous effect can also be obtainedwhen the light emitting elements are connected with the conductorwirings without using the conductive wires. For example, in a case wherethe light emitting elements are made of a nitride-based semiconductorusing a sapphire substrate, the electrodes are disposed on the samesurface side, so that, as shown in FIG. 1A, at least two electricallyconductive wires are needed to each of the light emitting elements.However, if the electrodes are arranged down and connected to theconductor wiring by using a metallic bonding member or the like, theelectric connection can be obtained without using the electricallyconductive wires. In such a case, the exposed region of the substrate,that is, an insulating portion is formed directly beneath the lightemitting elements, so that a light reflecting resin can also be appliedon the exposed region.

In addition, as shown in FIG. 1A, in a case where an electricallyconductive wire is used, at least a part of the electrically conductivewire and at least a part of the exposed region of the substrate arepreferably buried in the light reflecting resin. Particularly, if thesame resin is used to bury them, an advantageous effect such assimplifying the manufacturing steps can be obtained. The lightreflecting resin can also be provided in different steps.

Moreover, a protective element and an integrated circuit may be buriedin the light reflecting resin. With this arrangement, scattering andabsorbing of light can be reduced, and also it eliminates the need forseparately providing the mounting portions of such members, so that thelight emitting device can be downsized. A light emitting device using aprotective element will be described with reference to FIG. 3.

FIG. 3 is a partially sectional view of the light emitting device 300using a protective element 307, such as Zener diode and the like. Theexternal view of the light emitting device 300 is similar to that shownin FIG. 1A, and the shape of the light reflecting resin 302 is similarto that of the light emitting device 100 shown in FIG. 1A, and asectional view of a part thereof is shown for observation. As shown inFIG. 3, the conductor wirings 303A, 303B are provided on the substrate301 in the light emitting device 300. The light emitting elements 304are mounted on the conductor wiring 303A and connected with theconductor wirings 303A and 303B through the electrically conductivewires 305. The protective element 307 is mounted on the conductor wiring303B and fixed thereto by an electrically conductive bonding member, andalso connected to the conductor wiring 303A through the electricallyconductive wire. Then, the light reflecting resin 302 is disposed so asto cover the protective element 307.

Here, the protective element 307 is provided such that the protectiveelement 307 is entirely buried in the light reflecting resin 302. Withthis arrangement, absorption of light from the light emitting element304 can be prevented. It may be applicable that not a whole but at leasta part of the protective element is covered. In addition, it ispreferable that the electrically conductive wires connecting theprotective element and the conductor wiring are also buried in the lightreflecting resin.

The light reflecting resin in which the protective element to be buriedis preferably provided to also cover at least a part of the electricallyconductive wires connecting the light emitting elements and theconductor wiring. In addition, it is preferable that at least a part ofthe exposed region of the substrate is also buried in the lightreflecting resin. Further, the light reflecting resin is preferablyprovided to cover at least a part of the electrically conductive wires,at least a part of the exposed resin of the substrate, and at least apart of the protective element.

As described above, a member (an electrically conductive wire, aprotective element, and/or a substrate) which absorbs light from thelight emitting elements and a member (a (light transmissive) substrate)transmitting light in an unintended direction are buried in the lightreflecting member, and thus, a reduction in the light extractionefficiency can be suppressed.

The light reflecting member as described above is provided in the regionirradiated with the light from the light emitting elements, and arrangedto surround the light emitting elements. The height of the lightreflecting resin will be described with reference to FIGS. 4.

FIG. 4A is a perspective view of the light emitting device 400 having asealing member 406. FIG. 4B is a sectional view of a section taken alongline Y-Y′ of FIG. 4A of a light emitting device. FIG. 4C is a sectionalview of a section taken along line Z-Z′ of FIG. 4A of a light emittingdevice. In the present embodiment, the light emitting device 400 shownin FIG. 4A has an arrangement of the light emitting elements and theelectrically conductive wire and the like which are similar to that ofthe light emitting device 100 shown in FIG. 1A and which are buried inthe sealing member 406.

As shown in FIG. 4A, FIG. 4B, the light emitting device 400 has theconductor wirings 403A, 403B on the substrate 401. The light emittingelements 404 are mounted on the conductor wiring 403A and are connectedwith the conductor wiring 403B through the electrically conductive wire405 (the light emitting elements 404 are also connected to the conductorwiring 403A, but are not shown in the sectional view). Then, the lightreflecting resin 402 is disposed surrounding the light emitting elements404, and the region surrounded by the light reflecting resin 402 isfilled with the sealing member 406.

It is preferable that the height of the light reflecting resin is atleast the same as the light emitting layer of the light emittingelements or higher. In a case where the electrically conductive wire isused, as shown in FIG. 4B, the light reflecting resin is preferablydisposed higher than the highest portion of the electrically conductivewire 405.

When the sealing member 406 is filled in the region surrounding by thelight reflecting resin 402, the height of the light reflecting resin isadjusted so that the highest portion of the electrically conductivewires 405 is covered by the sealing member 406. Particularly, in a casewhere, as the sealing member 406, a liquid resin is disposed by drippingor the like, the height of the light reflecting resin 402 is preferablysuch that the liquid resin is prevented from flowing out over the lightreflecting resin surrounding the light emitting elements. In a casewhere the sealing member is provided by compression molding or printcoating, a sealing member may be disposed outside of the lightreflecting resin surrounding the light emitting elements.

In addition, as shown in the sectional view of FIG. 4C, the lightreflecting resin 402 is preferably disposed at a predetermined height (aheight approximately in parallel with the main surface of the substrate)with respect to the main surface (upper surface, lower surface) of thesubstrate 401. The shape of the light reflecting resin is not limitedthereto and an other shape may be employed according to the method ofdisposing the light reflecting resin.

For example, the light emitting device 500 shown in FIG. 5 is asectional view of a part of the light reflecting resin corresponding tothe sectional view taken along line Z-Z′ of FIG. 4A, and has a lightreflecting resin 502 having a shape in which a part of the lightreflecting resin bulges out, which is different than the lightreflecting resin 402 having a flat surface as shown in FIG. 4C.Specifically, a part of the light reflecting resin 402 of the lightemitting device 400 shown in FIG. 4A, which is a part of the lightreflecting resin 502B corresponding to the position where thelongitudinal light reflecting resin and the lateral light reflectingresin intersect is formed somewhat higher than the rest of the lightreflecting resin 502A.

Such a shape of the light reflecting resin having a bulging part can beformed by discharging a resin of high viscosity from a nozzle inlongitudinal direction and lateral direction onto the substrate prior todividing. Particularly, in a case where the light emitting element has aprotective element 307 as shown in FIG. 3, by disposing the protectiveelement in a region where the light reflecting resin to be disposedhigher than other regions, the entire protective element that isrelatively tall can be buried in the light reflecting resin.

It is preferable that the surfaces (inner wall) of the light reflectingmember facing the light emitting elements are formed inclined wideningupward as shown in the partially sectional view of FIG. 4B, for example.In FIG. 1B, both the inner walls and the outer walls are made asinclined surfaces, but either only one of them (for example, the innerwalls) may be made inclined. In addition, in FIG. 1B, a part between theinner wall and the outer wall is rounded, but the shape is not limitedthereto and other shape may be employed such as a shape having a flattop.

Moreover, the distance between the inner shape and the outer shape ofthe light reflecting resin, that is, the width of the light reflectingresin in top plan view can be adjusted according to various factors suchas the size of the substrate, the size of the light emitting element tobe mounted. In addition, the distance is preferably selected also inview of balance with the height.

The inner shape of the light reflecting resin disposed surrounding thelight emitting elements will be described referring to FIG. 1C, FIG. 8etc. FIG. 1C, FIG. 8 are top plan views of the light emitting devices100, 800, in which the conductor wirings 103A, 803A are disposed on theapproximately rectangular substrates 101, 801 and the light emittingelements 104, 804 are mounted thereon, respectively. The light emittingelements and the conductor wirings are connected by the electricallyconductive wires 105, 805. The electrically conductive wires in thevicinity of the connect portion are buried in the light reflecting resin102, 802, respectively, and therefore not shown in the figures. Theinner shape of the light reflecting resin disposed surrounding the lightemitting elements may be formed approximately rectangular in top planview, as shown in FIG. 1C. The shape thereof is not limited thereto, andas shown in FIG. 8, an approximately rectangular shape with roundedcorners may be employed. Particularly, in a case where a high viscosityresin is applied as the light reflecting resin, a shape with roundedcorners as shown in FIG. 8 can be obtained by providing the lightreflecting resin in longitudinal direction and lateral directionintersecting each other before hardening so that they mix and merge.Such a shape facilitates light to be reflected evenly. The shape is notlimited to that described above and, an appropriate shape such as acircle, an oval, or a polygon in plan view may be employed according todesired emission properties or the like.

Further, in the present invention, the light reflecting resin may bedisposed to reach a side surface of the light emitting elements. In thiscase, the inner shape corresponds to the shape of the light emittingelements and the arrangement thereof.

In addition, in the light emitting device shown in such as FIG. 1C has alight reflecting resin disposed to surround a plurality of the lightemitting elements, but the arrangement is not limited thereto, the lightreflecting resin may be disposed top surround a single light emittingelement, or to surround two or more light emitting elements. Asdescribed above, when the light reflecting resin is closely arranged andthe electrically conductive wires which absorbs light or the substratewhich transmits/absorbs light is buried therein, loss of light can bereduced efficiently.

The outer shape of the light reflecting resin disposed surrounding thelight emitting elements will be described referring to FIG. 1C, FIG. 7etc. FIG. 1C, FIG. 7 are top plan view of the light emitting devices100, 700, in which the conductor wirings 103A, 703A are disposed on theapproximately rectangular substrates 101, 701 and the light emittingelements 104, 704 are mounted thereon, respectively. The light emittingelements and the conductor wirings are connected by the electricallyconductive wires 105, 705. The electrically conductive wires in thevicinity of the connect portion are buried in the light reflecting resin102, 702, respectively, and therefore not shown in the figures. Theouter shape of the light reflecting resin arranged surrounding the lightemitting elements may be such that, as shown in FIG. 7 in top plan view,the outer edge of the light reflecting resin 702 is placed apart fromthe outer edge of the substrate 701. In this case, the outer edge of thesubstrate and the outer edge of the light reflecting resin arepreferably made in the same shape but different size. In a case wherethe substrate 701 is approximately square as shown in FIG. 7, it ispreferable that the outer edge of the light reflecting resin 702 is alsomade in approximately square shape with respective sides beingapproximately in parallel.

As described above, when the outer edge of the substrate and the outeredge of the light reflecting resin are spaced apart from each other, inother words, when the outer edge of the light reflecting resin is madesmaller than the outer edge of the substrate, dividing step in apost-process can be facilitated. Particularly, in a case where a resinhaving different hardness or the like than that of the substrate is usedas the light reflecting resin, for example, in a case where a lightreflecting resin having lower hardness and higher ductility than aceramic substrate is disposed on the ceramic substrate, the laterdividing step (step to form single chips) may be difficult to perform(difficult to divide). Therefore, the outer edge (that is, the dividingposition) of the substrate only includes the substrate, dividing can beperformed with a good process yield.

The dividing step will now be described below. FIG. 9A and FIG. 9B areviews respectively showing a part of light emitting device aggregationprior to dividing the substrate, FIG. 9A illustrates a state beforedisposing a light reflecting resin and FIG. 9B illustrates a state afterdisposing the light reflecting resin 902. As shown in FIG. 9A, theconductor wirings 903A, 903B are disposed on the substrate 901 and thelight emitting elements 904 are mounted thereon, and the light emittingelements and the conductor wirings are electrically connected by usingthe electrically conductive wires 905. Thereafter, as shown in FIG. 9B,the light reflecting resin 902 is disposed surrounding the lightemitting elements 904. Here, the light reflecting resin 902 is disposedto intersect longitudinally and laterally, and the dividing positionsare shown by arrows in the figure. With this arrangement, formation ofthe light reflecting resin can be facilitated and the dividing step canbe carried out relatively easily. However, the shape or method is notlimited thereto, and other methods such as print coating can beemployed.

In addition, the outer shape (outer edge) of the light reflecting resinmay correspond to the shape of the substrate.

Further, the outer edges of the substrate and the light reflecting resin(outer shapes) can be different. For example, as shown in FIG. 1A, thelight reflecting resin 102 may includes a first region A which is spacedapart from the outer edge of the substrate 101 and a second region Bwhich is in contact with (coincident with) the outer edge of thesubstrate.

Disposing only a part of the light reflecting resin spaced apart fromthe outer edge of the substrate, in other words, exposing a part of thesubstrate, allows a part of the dividing (cutting) position to be onlythe substrate, so that dividing (cutting) can be carried out with goodproductivity. As described above, in a case where the light reflectingresin is also cut at a part of the dividing position, the productivitywill be somewhat lower than the case where only the substrate isdivided, however, it will be advantageous that the adhesion area betweenthe light reflecting resin and the substrate can be increased andfurther, the step of disposing the light reflecting resin can besimplified. In addition, as shown in FIG. 8, the intersecting portionsof the longitudinally and laterally provided light reflecting resin canbe formed rounded.

In addition, the first region of the light reflecting resin ispreferably disposed to be interposed between the second regions at aside of the substrate. With this arrangement, the adhesion area betweenthe light reflecting resin and the substrate can be increased. Inaddition, in a case where a lens member is disposed on the lightreflecting resin, the adhesion with the lens member can also beimproved.

Further, the second region of the light reflecting resin is preferablyspaced apart from the corners of the substrate. With this arrangement,the light reflecting resin can be prevented from detaching from thesubstrate. In addition, provision of a mark and the like at a corner ofthe substrate to indicate the dividing positions and prevent the markfrom being covered by the light reflecting resin, dividing positionalaccuracy can be improved.

For the specific material of the light reflecting resin, a member whichabsorbs little or no light but effectively reflect the light from thelight emitting elements is preferable. In a specific example, thereflectivity is preferably at least 50%, and more preferably 70% orhigher. In a case where the light reflecting resin has a lightscattering property, measurement of the reflectivity may be difficult,but in such a case, the reflectivity can be measured as a referencevalue by such a method in which a ratio proportional to the standarddiffuser is determined by using an integrating sphere.

In addition, an insulating member is preferable for the light reflectingresin, and a member resistant to deterioration by light from the lightemitting elements and outside light is preferable for the lightreflecting resin. Also, a thermosetting resin, a thermoplastic resin, orthe like, a resin having a certain degree of strength can be used forthe light reflecting resin. Specific examples thereof include a phenolresin, a glass epoxy resin, a BT resin, and a PPA resin. Addition of areflecting member (for example, TiO₂, Al₂O₃, ZrO₂, or MgO) whichreflects light from the light emitting elements to the resin base bodyallows to reflect light effectively.

Such a light reflecting resin can be disposed easily by discharging ahigh viscosity resin from a nozzle of a predetermined size (width) aftermounting the light emitting elements and the protective element to bedescribed later, on the conductor wirings. In addition, the lightreflecting resin can be disposed by using a method such as a printcoating. The light reflecting resin disposed as described above canserve as a protective member protecting the light emitting elements orthe like, after being hardened by heat, light, or the like.

Substrate

A substrate is an insulating member to which a conductor wiring isprovided. An approximately tabular member capable of providing a lightreflecting resin thereon and/or of mounting a light emitting element,protective element, or the like, thereon may be provided on thesubstrate. Examples of the substrate material include glass epoxy resin,ceramics, glass, and plastic. Particularly, as ceramics, alumina,aluminum nitride, mullite, silicon carbide, or silicon nitride ispreferable. Examples of plastic include epoxy resin, polyimide resin orthe like. A substrate having high heat resistance can be obtained byusing such a material.

Conductor Wiring

A conductor wiring is disposed on an upper surface of the substratecontinuous to the back surface of the substrate through an inner portionor a surface of the substrate, and serves to establish an electricconnection with an external device. The size and shape of the conductorwiring can be selected variously, for example, as the light emittingdevice 100 shown in FIGS. 1A to 1C, the conductor wiring may be disposedwidely so that an end portion thereof is buried in the light reflectingresin 102, or as the light emitting device 200 shown in FIG. 2, theconductor wiring 203A having a portion spaced apart from the lightreflecting resin 202 may be disposed and on which the light emittingelements 204 are provided. The conductor wiring may also include amember having no electrical connection with an external device andserving as a light reflecting member.

These conductor wiring is to be disposed such that at least twoconductor wirings serving as at least a pair of positive and negativeelectrodes, for example, the conductor wirings 1030A, 1030B as shown inFIG. 10A, are to be formed on the substrate which has been divided inthe third step (dividing step) to be described later. The position,size, shape, or the like of the conductor wiring are appropriatelyadjusted according to the substrate, the number of the light emittingelements, or the like. In FIG. 10A, all of the light emitting elements1040 are mounted on the conductor wirings 1030A, but it is not limitedthereto. The light emitting elements 1040 may be mounted on theconductor wirings 1030A, 1030B, respectively.

The conductor wiring 1030C is made of the same material as the conductorwirings 1030A, 1030B each of which serves as an electrode, but theconductor wiring 1030C is provided as a mark (cathode mark/anode mark)for indicating the polarity of the light emitting device and is not forelectrical connection. It is preferable that the conductor wirings 1030Care also disposed at the positions such that each of which will be oneach of the divided substrate. The size and shape thereof can beselected appropriately.

Specific examples of the conductor wiring include metals such as copper,aluminum, gold, silver, tungsten, iron, and nickel, or iron-nickelalloy, phosphorus bronze, copper containing iron, or the like.

Sealing Member/Lens Member

A sealing member is a member provided in or outside of a regionsurrounded by the light reflecting resin, to protect the light emittingelements and the protective elements or the like, from dust, moisture,external force, or the like. In addition, the sealing member preferablyhas light transmissive property which allows light from the lightemitting elements transmits therethrough, and resistance to such light.Specific examples thereof include a silicone resin, an epoxy resin, anda urea resin. In addition to above-described materials, a coloringagent, a light diffusing agent, a filler, a color conversion member(fluorescent member) or the like, can be included as needed.

The filling amount of the sealing member is needed to be sufficient tocover the semiconductor light emitting element, the protective elementsuch as Zener diode, and a conductive wire, or the like.

The surface shape of the sealing member can be suitably selectedaccording to the light distribution properties and the like. Forexample, as shown in FIG. 4B, the sealing member can be filled as thesame as or lower the height of the light reflective resin 402. Here, thesealing member is formed in a concave shape in which the center portionis somewhat lower than the surrounding portion, but the shape is notlimited thereto, a shape having a flat top surface or a convex shape inwhich the center portion is higher than the surrounding portion can beemployed.

In addition to the sealing member, a lens member may also be disposed.For example, as the light emitting device 600 shown in FIG. 6, a lensmember extending the outer edge of the substrate 601 and having ahemisphere shape can also be disposed. Here, the lens member 608 isprovided such that the lens has a spherical shape part somewhatexternally above the light reflecting resin 602.

The light from the light emitting elements 604 hardly reaches theexternal sides of the light reflecting resin 602, therefore, the lensshape is not needed. With such a shape, when the individual chips areformed (dividing) after disposing the lens member, the dividing can becarried out without damaging the lens portion (the spherical shapepart). Therefore, adverse effect on the optical properties can besuppressed. In addition, as described above, when the lens member 608 isprovided as a different member than the sealing member 606, for example,in a case where a wavelength converting member (a fluorescent member) isused as will be described below, the fluorescent member can be mixedonly to the sealing member 606. Therefore, the amount of the fluorescentmember needed to obtain a desired emission color can be easilydetermined, and the lens portion can be formed using only a resin, sothat adjustment of the light distribution properties can be facilitated.The curvature and size of the lens can be selected variously accordingto the desired light distribution properties.

Moreover, the lens member can be formed not only in a hemispherical lensshape as shown in FIG. 6, but also in a shape with a recess portioncapable of laterally reflecting light, a Fresnel lens shape, or thelike. Forming the lens member in a hemispherical shape allows adjustingthe directional characteristics. In addition, a diffusing agent, apigment, a wavelength converting member, or the like, can be mixeddepending on the purpose and intended use.

Die Bonding Resin

Die bonding member is a bonding member for mounting a semiconductorlight emitting element, the protective element or the like on a basesubstrate or a conductive member. Depending on the substrate whereon theelement is mounted, either a conductive die bonding member or aninsulating die bonding member can be elected. For example, eitherinsulating or conductive die bonding member can be used for asemiconductor light emitting element in which a nitride semiconductorlayers are stacked on a sapphire substrate which is an insulatingsubstrate. When a conductive substrate such as SiC substrate is used,conduction can be established by using a conductive die bonding member.Examples of the insulating die bonding member include an epoxy resin anda silicone resin. When the above described resins are used, a metallayer having high reflectivity such as an Al layer may be provided onthe back surface of the semiconductor light emitting element, inconsideration of deterioration due to light and heat from thesemiconductor light emitting element. In this instance, a method such asvacuum evaporation, sputtering, or thin layer bonding can be employed.Examples of conductive die bonding members include a conductive pastecomprising silver, gold, or palladium, a solder such as Au—Sn eutectic,and a brazing filler metal such as a low melting temperature metal.Moreover, among such die bonding members, especially when a transparentdie bonding member is used, a fluorescent member which absorbs lightfrom the semiconductor light emitting element and emits light indifferent wavelength can be included.

Electrically Conductive Wire

Examples of the electrically conductive wire which connect theelectrodes of a light emitting element and the electrically conductivemembers include an electrically conductive wire made of a metal such asgold, copper, platinum, and aluminum, and an alloy thereof.Particularly, gold excellent in thermal resistivity or the like ispreferably used.

Wavelength Converting Member

In the above described transparent member, a fluorescent member whichabsorbs at least part of light from the semiconductor light emittingelement and emits light in different wavelength may be included as awavelength converting member.

It is more efficient when a fluorescent member converts light from thesemiconductor light emitting element to a light with longer wavelength.The fluorescent member may comprise a single layer made of a fluorescentmaterial etc., may comprise a single layer made of mixture of two ormore fluorescent materials etc., may comprise two or more stacked layersof single layers each of which made of a fluorescent material etc., ormay comprise two or more stacked layers of single layers each of whichis made of a mixture of two or more fluorescent materials etc.

The fluorescent member is needed to, for example, absorb light from asemiconductor light emitting element comprising a nitride semiconductoras a light emitting layer and converts it to light of a differentwavelength. The fluorescent material is preferably at least one selectedfrom among nitride fluorescent materials and oxynitride fluorescentmaterial that is mainly activated with lanthanoid elements such as Euand Ce; alkaline earth halogen apatite fluorescent material that ismainly activated with lanthanoid elements such as Eu and transitionmetal elements such as Mn; alkaline earth metal halogen-boratefluorescent material; alkaline earth metal aluminate fluorescentmaterial; rare earth element aluminate fluorescent material that ismainly activated with alkaline earth silicate, alkaline earth sulfide,alkaline earth thiogallate, alkaline earth silicon nitride, germanate,or lanthanoid elements such as Ce; and organic and organic complexesthat are mainly activated with rare earth silicate or lanthanoidelements such as Eu.

Example of the rare earth aluminate phosphor that is mainly activated bylanthanoid elements such as Ce include YAG based phosphor represented bythe formulas: Y₃Al₅O₁₂:Ce, (Y_(0.8)Gd_(0.2))₃Al₅O₁₂:Ce,Y₃(Al_(0.8)Ga_(0.2))₅O₁₂:Ce and (Y, Gd)_(3(Al, Ga)) ₅O₁₂. It alsoincludes Tb₃Al₅O₁₂:Ce and Lu₃Al₅O₁₂:Ce in which portion or all of Y issubstituted with Tb or Lu.

It is possible to use a phosphor which is other than the phosphordescribed above and has the same performances and effects as those ofthe fluorescent materials.

Semiconductor Light Emitting Element

In the present invention, a light emitting diode is preferably used as asemiconductor light emitting element.

A semiconductor light emitting element having any output wavelength canbe selected. For constructing blue and green light emitting elements,ZnSe and nitride semiconductor (In_(X)Al_(Y)Ga_(1-X-Y)N, 0≦X, 0≦Y,X+Y≦1) may be used. For constructing red light emitting elements, GaAs,InP, and the like may be used. Further, a semiconductor light emittingelement made of materials other than those described above may also beused. Composition, emitting color, size, and number of the lightemitting elements can be selected arbitrarily according to purpose.

Examples of such semiconductor light emitting elements comprise varioussemiconductors such as ZnSe and GaN. However, a nitride semiconductor(In_(X)Al_(Y)Ga_(1-X-Y)N, 0≦X, 0.1≦Y, X+Y≦1) capable of emitting lightwith a short-wavelength which sufficiently excites the fluorescentmaterial is preferable. Various wavelengths of emission can be selectedaccording to the materials and the mixed crystal ratio of thesemiconductor layer.

In addition, a light emitting element capable of emitting light which isnot only in visible light range but also ultraviolet light and infraredlight can be formed. Further, along with a semiconductor light emittingelement, an optical detector element or the like can be mounted.

Resin Discharge Device

The resin discharge device is used for disposing the light reflectingresin in the second step. For example, as shown in such as FIG. 10B,using the air pressure, the device is capable of discharging liquidresin continuously or in a dot shape.

Light Emitting Device Manufacturing Method

According to an embodiment of the present invention, a method ofmanufacturing a light emitting device includes the following steps.

In a first step, a light emitting element is mounted on a substratehaving a conductor wiring and electrically connecting the light emittingelement with the conductor wiring. In a second step, a light reflectingresin which reflects light from the light emitting element is disposedon the substrate to surround the light emitting element. In a thirdstep, a sealing member is disposed after hardening the light reflectingresin to cover the light emitting element.

The manufacturing method may be further provided with at least one offollowing steps. The light reflecting resin is disposed by discharging aliquid resin from a resin discharge device. The resin discharge deviceis moved while discharging the liquid resin over the substrate. In afourth step, the substrate is divided after hardening the sealing memberdisposed in the third step, wherein the resin discharge device is movedover a dividing position of the substrate of the fourth step whiledischarging the liquid resin. The resin discharge device is mover over aregion spaced apart from the dividing position of the fourth step. Theresin discharge device is moved over the substrate in longitudinaldirection and lateral direction to dispose a first light reflectingresin, then, the resin discharge device is moved over the first lightreflecting resin to dispose a second light reflecting resin at least apart thereof being in contact with the first light reflecting resin. Aliquid resin is discharged while the resin discharge device is at restand discharge of the resin is interrupted while the resin dischargedevice is moving. The first light reflecting resin and the second lightreflecting resin are disposed spaced apart from a dividing position ofthe fourth step and in contact with each other. A mask covering havingan opening surrounding the light emitting element is used over the lightemitting element, and the light reflecting resin is discharged from theopening to dispose the light reflecting resin. In the first step, anelectrically conductive wire is used for connection, and in the secondstep, at least a part of the electrically conductive wire is covered.The first step includes a step of mounting a protective element andelectrically connecting the conductor wiring and the protective element,and the second step includes a step of covering the protective element.The first light reflecting resin and the second light reflecting reinare disposed overlapping over the protective element.

EMBODIMENT 1

Embodiment 1 of a method of manufacturing a light emitting deviceaccording to the present invention will be described below.

A light emitting device 2000 obtained according to the present method isshown in FIG. 11A to FIG. 11C. FIG. 11A is a perspective view of thelight emitting device 2000, FIG. 11B is a sectional view taken alongline Y-Y′ of FIG. 11A, and FIG. 11C is a top plan view of the sealingmember 2060 of FIG. 11A in its transparent state. As shown in FIG. 11C,the corners of the light reflecting resin 2020 have a rounded shape, butthe rounded shape is omitted in FIG. 11A for simplify.

In the present embodiment, a light emitting device 2000 includes anapproximately rectangular substrate 2010 having conductor wiring 1030A,1030B, and 1030C provided on its top surface, and a plurality of lightemitting elements 2040 mounted on the conductor wiring 1030A. The lightemitting elements 2040 are electrically connected with the conductorwirings 2030A, 2030B through the electrically conductive wires 2050.

Then, a light reflecting resin 2020 which reflects light from the lightemitting elements is disposed surrounding the light emitting elements2040. With this arrangement, light can be reflected efficiently and thelight extraction efficiency can be improved. In addition, disposing sucha light reflecting resin 2020 to cover a part of the electricallyconductive wires 2050 allows minimizing the exposure of the electricallyconductive wires and suppresses absorption of light. Thus, the opticaloutput can be further improved.

In the present embodiment, the light reflecting resin 2020 is disposedto the end portion of the substrate 2010. With this arrangement, thelight reflecting resin in a plurality of the light emitting devicesproduced from a single substrate can be disposed relatively easily andefficiently.

The light emitting devices as described above can be obtained throughthe steps as shown in FIG. 10A to FIG. 10E.

FIG. 10A to FIG. 10E are figures sequentially showing a method ofmanufacturing the light emitting devices to obtain the light emittingdevices as shown in, such as FIG. 11A, and illustrating the steps whichare carried out on the substrate 1010 prior to dividing. Here, anaggregation of four light emitting devices is illustrated, but inpractice, a substrate having a size capable of providing many more lightemitting devices are used, and a part thereof is shown in the figures.In addition, the substrates of before and after the dividing will bereferred to simply a substrate.

1-1. First Step

In the first step, the light emitting elements are mounted on asubstrate having the conductor wirings, and the light emitting elementsand the conductor wirings are electrically connected respectively. FIG.10A shows the state in which the first step has been completed. As shownin FIG. 10A, in the aggregation 100 of the light emitting devices, theconductor wirings 1030A, 1030B, and 1030C are disposed on the uppersurface of the substrate 1010. The shape, size, arrangement of theconductor wirings are not limited to that shown in FIG. 10A and can beselected appropriately.

Such a conductor wiring can be obtained, for example, in a case where aceramic substrate is used, by applying an electrically conductive pastecontaining fine particles of a high melting point metal such as tungstenand molybdenum in a predetermined pattern in a step of unbaked ceramicsgreen sheet, then, baking it. Further, after baking the ceramics greensheet, nickel, gold or silver may be plated on the conductor wiringswhich are previously disposed. In the present invention, the term“conductor wiring” includes the plated metal.

In a case where a ceramics substrate is used, as described above, otherthan to dispose the conductor wirings and the insulating portionsintegrally, the conductor wirings can be disposed on a ceramics platethat is baked previously.

In a case glass epoxy resin is used for the substrate, a copper plate isattached to an epoxy resin containing glass cloth or a partiallyhardened epoxy resin prepreg and then thermally harden it. After that, adesired pattern is formed in the copper plate by using photolithographyto obtain the conductor wirings.

Using a die bonding member (bonding member), the light emitting elements1040 are mounted on the conductor wirings 1030A having a large areaamong the conductor wirings shown in FIG. 10A formed as described above.Here, 6 pieces of rectangular light emitting elements are used andarranged in 3×2 lines, but the configuration is not limited thereto, thelight emitting element of other shapes such as square can be used, andalso with an appropriate arrangement.

The conductor wirings 1030A, 1030B and the light emitting elements 1040are electrically connected through the electrically conductive wires1050, respectively. The connection between the conductor wirings and thelight emitting elements can be made either directly or indirectly,through the electrically conductive wires. Here, the light emittingelements 1040 which are directly connected to the conductor wirings1030A and the conductor wirings 1030B through the electricallyconductive wires 1050, respectively are mixed with the light emittingelements 1040 and which are indirectly connected via the adjacent lightemitting elements, but the connection is not limited thereto, a variousways of connection can be employed. In addition, without using anelectrically conductive wire, the connection can be made by using anelectrically conductive bonding member. The conductor wiring 1030C ismade of the same material as the conductor wirings 1030A, 1030B each ofwhich serves as an electrode, but the conductor wiring 1030C is providedas a mark (cathode mark/anode mark) for indicating the polarity of thelight emitting device and is not for electrical connection.

In addition other than the light emitting elements, a protective elementcan be provided. The protective element is electrically connected to theconductor wiring by using an electrically conductive wire as in thelight emitting elements. In this case, it is preferable to dispose aprotective element at a position where the light reflecting resin to bedisposed in a post-process. With this arrangement, absorption of lightby the protective element can be reduced. Moreover, since a protectiveelement is not provided between the light emitting elements and thelight reflecting resin, a more uniform light distribution can beobtained. Further, the protective element is buried in the lightreflecting resin, downsizing of the light emitting element can beachieved.

1-2. Second Step

In the second step, a light reflecting resin which reflects light fromthe light emitting elements is disposed to surround the light emittingelements.

1-2-1. Second Step (1)

FIG. 10B is a view illustrating a step of disposing the light reflectingresin 1020 (1020A) by using a resin discharge device 10000 on thesubstrate 1010 whereon the light emitting elements obtained in the firststep have been mounted. In the present embodiment, first, a first lightreflecting resin 1020A is disposed as shown in FIG. 10B, and next, asecond light reflecting resin 1020B is disposed as shown in FIG. 10C.Thus, the light reflecting resin 1020 surrounding the light emittingelements is disposed in the two steps.

The resin discharge device 10000 is capable of moving (movable) inup-and-down direction or in lateral direction with respect to thesubstrate 1010, above the fixed substrate 1010. Typically, a syringe forstoring a resin and a regulator for controlling the discharge pressureor the like are equipped to the main body (not shown) to which the resindischarge device 10000 as shown in FIG. 10B and the like is attached.

In the present specification, the nozzle 10100 for discharging the resinis shown in the figures as the resin discharge device 10000 and otherparts are omitted. The steps below will be described mostly withreference to this part. In the figures, an example is illustrated with asingle resin discharge device, but it is not limited thereto, aplurality of the devices can be attached to the main body. With thisarrangement, a plurality of lines of the light reflecting resin can bedisposed at the same time.

FIG. 16A to FIG. 16C are figures showing the shape of the nozzle. Theouter shape of the nozzle may be such as a cylindrical tube as shown inFIG. 16A, quadrangular tube as shown in FIG. 16B, or a tube with atapered end as shown in FIG. 16C. In addition, the shape of the openingcan also be variously selected. For example, a circular opening 70300Aas shown in FIG. 16A, a quadrangular opening 70300B as shown in FIG.16B, and a rectangular opening 70300C as shown in FIG. 16C or the like,can be employed.

In the present embodiment, firstly as shown in FIG. 10B, the resindischarge device 10000 is moved while discharging a liquid resin fromthe nozzle 10100 at its tip to dispose the light reflecting resin 1020in the vicinity of the light emitting devices 1040.

In this embodiment, the resin discharge device 10000 is moved in onedirection (longitudinal direction or lateral direction), for example, inthe direction indicated by an arrow la in the figure. At this time, theresin discharge device 10000 for covering a part of the electricallyconductive wires 1050 with the light reflecting resin 1020 is movedabove and in the vicinity of the light emitting elements 1040. With thisarrangement, a linear first light reflecting resin 1020A can be disposedin the vicinity of the light emitting elements 1040.

All of the moving directions of the resin discharge device 10000 can bethe same, for example in a direction indicated by arrow 1 a in FIG. 10B.That is, a plurality of the light reflecting resin 1020A are disposed inparallel to each other, and all of them can be disposed by moving theresin discharge device 10000 in the direction indicated by arrow A.Alternatively, after moving in the direction of arrow A, when theadjacent light reflecting resin 1020A is to be disposed, the resindischarge device 10000 may be moved in the opposite direction.

1-2-1.1. Second Step (2)

Next, as shown in FIG. 10C, the resin discharge device 10000 is moved inthe direction indicated by arrow 1 b in the figure, that is, in adirection intersecting the first light reflecting resin 1020A which ispreviously disposed, to dispose the second light reflecting resin 1020Bso as to surrounding the light emitting elements 1040. At this time, theresin discharge device 10000 may be moved above the substrate 1010, theconductor wirings 1030A, 1030B, and further, above the light reflectingresin 1020A disposed previously, while discharging the liquid resin.Alternatively, discharging of the resin may be interrupted above thelight reflecting resin 1020A.

As described above, first, the resin discharge device is moved in adirection along the substrate to dispose the light reflecting resin, andthen, the resin discharge device is moved in a direction approximatelyorthogonal to the previously disposed light reflecting resin to disposethe light reflecting resin. That is, the step of disposing the lightreflecting resin is carried out in two or more steps. With thisarrangement, the aggregate of the light emitting devices 1000 as shownin FIG. 10D can be obtained.

The moving speed of the resin discharge device 10000 can beappropriately adjusted according to the viscosity, temperature, or thelike, of the resin. In order to dispose a plurality of light reflectingresins of approximately the same width, it is preferable to move thedevice at a constant speed at least while discharging the resin. In acase where the discharge of the resin is interrupted while the device isin motion, the moving speed in the interval can be changed.

The discharge rate of the resin is also preferably constant. Further,both the moving speed of the resin discharge device and the dischargerate of the resin are preferably constant. Adjustment of the dischargerate can be achieved by maintaining the pressure applied at dischargingor the like constant.

In FIG. 10B, the resin discharge device 10000 moves above the locationsalong which the substrate is to be divided in a post-process, whiledischarging the liquid resin. In a case where a number of the lightemitting devices are produced by using the same substrate, moving theresin discharge device while continuously discharging a liquid resin asdescribed above, the light reflecting resin can be easily formed with auniform shape. Discharge can be interrupted to avoid the dividinglocations, which will be described below.

The light reflecting resin 1020 can be provided on the conductor wirings1030A, 1030B or on the substrate 1010, or on the both, at a portionsurrounding the light emitting elements 1040. For example, in FIG. 10B,the light reflecting resin 1020 is disposed so as to cover a part of theconductor wiring 1030A and the entire conductor wiring 1030B. With thisarrangement, the substrate 1010 exposed between the conductor wiring1030A and the conductor wiring 1030B can also be covered. Thus, in acase where a member made of glass epoxy resin or ceramic and capable oftransmitting light relatively easily is used as a material of thesubstrate 1010, light can be prevented from leaking out from the exposedportion, so that a reduction in the light extraction efficiency of thelight emitting device can be suppressed.

Moreover, the light reflecting resin can be disposed so as also to covera part of the electrically conductive wires. For example, as shown inFIG. 10B, by moving the resin discharge device 10000 pass through abovethe connection between the conductor wiring 1030B and the electricallyconductive wire 1050, a part of the electrically conductive wire 1050can be buried in the light reflecting resin 1020. With this arrangement,absorption of light by the electrically conductive wires can be reduced.For example, in a case where a light emitting element made of anitride-based semiconductor and emits blue light is used and a gold wireis used as the electrically conductive wire, the blue emission isabsorbed by the gold wire. As in the present invention, by covering evena part of the electrically conductive wire with a light reflectingresin, loss of light can be reduced and the light extraction efficiencyof the light emitting device can be improved.

Further, in a case where a protective element is used, the first lightreflecting resin and the second light reflecting resin are preferablydisposed overlapping over the protective element. With this arrangement,the protective element can be covered easily.

1-3. Third Step

In the third step, after the light reflecting resin is hardened in thesecond step, a sealing member is disposed to cover the light emittingelements. FIG. 10E is a figure showing an aggregate 1000 of the lightemitting devices in which a sealing member 1060 is disposed on theaggregate 1000 of the light emitting devices obtained in FIG. 10D. Inthis figure, the sealing member 1060 is disposed so as to fill the innerside of the light reflecting resin 1020 which is disposed in aframe-shape surrounding the light emitting elements 1040. With thisarrangement, the light emitting elements 1040 can be protected fromdust, moisture, external force or the like. In FIG. 10E, the sealingmember 1060 is disposed to fill the region K surrounded by the lightreflecting resin 1020. In addition to this, the sealing member 1060 canbe disposed in the region L and the region M where a light emittingelement is not mounted.

In the third step, a liquid resin different than the light reflectingresin is used. A method appropriate to meet the need, such as a methodof disposing the sealing member to fill the region surrounded with thelight reflecting resin by using the resin discharge device 10000 asshown in, such as FIG. 10A (potting molding), a method of filling alight transmissive resin in a mold with a desired shape (compressionmolding, transfer molding), a method of disposing the resin by using amask (print molding), and spray coating, can be used.

1-4. Fourth Step

In the fourth step, after hardening the sealing member disposed in thethird step, the substrate is divided to obtain individual light emittingdevices.

It is preferable to set the dividing positions to avoid the lightreflecting resin surrounding the light emitting elements, as indicatedby lines X-X′ and X′-X′ in FIG. 10E. That is, the regions L and theregions M are divided so that the regions K, where the sealing member106 is provided, are intact and remain as the light emitting devices. Atthis time, a dividing method in two steps can be used, in which firstlyonly the light reflecting resin 1020 on the substrate 1010 is dividedand secondly the substrate 1010 is divided. For example, in a case wherethe dividing is carried out by using a cutting blade, the lightreflecting resin 1020 is cut to a depth approximately reaches the uppersurface of the substrate 1010, or to a depth slightly cut into the uppersurface of the substrate 1010, and then, the substrate 1010 remaining atthe same location is cut. As described above, by carrying out a step inparts according to the member to be cut, stress created at the time ofcutting can be reduced and dividing can be carried out with goodaccuracy. However, it is not limited thereto, the light reflecting resinand the substrate can be cut in a single step.

For the dividing, various methods such as dicing, laser irradiation, orthe like, can be selected.

In the light emitting devices obtained as described above, as shown inFIG. 11C, the light reflecting resin 2020 is disposed in the vicinity ofthe light emitting elements 2040, and particularly, is disposed so closethat the connecting portions between the electrically conductive wires2050 and the conductor wirings are buried. Therefore, the loss of lightfrom the light emitting elements 2040 can be reduced.

EMBODIMENT 2

A light emitting device 3000 obtained in Embodiment 2 is shown in FIG.12. FIG. 12 is a top plan view of the light emitting device 3000.

FIG. 13A and FIG. 13B are figures illustrating a second step inEmbodiment 2 for disposing a light reflecting resin in a method ofmanufacturing a light emitting device to obtain a light emitting device3000 shown in FIG. 12.

The steps in Embodiment 2 other than the second step can be similar tothat of Embodiment 1, and therefore omitted.

2-2. Second Step

In the second step, a light reflecting resin which reflects light fromthe light emitting elements is disposed to surround the light emittingelements. In Embodiment 2, the light reflecting resin is not disposed atthe dividing positions in the light emitting device 3000, which isdifferent from Embodiment 1. The same resin discharge device as inEmbodiment 1 is used.

2-2-1. Second Step

FIG. 13A is a view illustrating a step of disposing the light reflectingresin 4020 (4020A) by using a resin discharge device 40000 on thesubstrate 4010 whereon the light emitting elements obtained in the firststep have been mounted. The light reflecting resin 4020 can be disposedsurrounding the light emitting elements by both the step shown in FIG.13A and the following step shown in FIG. 13B.

Firstly, as shown in FIG. 13A, the resin discharge device 40000 is movedin the direction indicated by arrow 4 a while discharging a liquid resinfrom the nozzle 40100 at its tip to dispose the first light reflectingresin 4020A in the vicinity of the light emitting devices 4040. At thistime, the disposition is carried out avoiding the dividing positions(line 4X-4X′, line 4X′-4 x′ in the figure). Such a deposition can beobtained by repeating discharge and interrupt of the resin from theresin discharge device 40000.

Next, as shown in FIG. 13B, the resin discharge device 40000 is moved inthe direction indicated by arrow 4 b in the figure, that is, in adirection intersecting the first light reflecting resin 4020A which ispreviously disposed, to dispose the second light reflecting resin 4020Bso as to surrounding the light emitting elements 4040. Here, the lightreflecting resin is also disposed avoiding the dividing positions.

2-2-2. Alternative Method of Second Step 1

FIG. 14 is a figure illustrating an alternative method of second step.

Here, as shown in FIG. 14, the resin discharge device 50000 is movedabove the substrate 5010 while discharging the resin sequentially in thedirections indicated by arrows 5 a, 5 b, 5 c, and 5 d in the figure. Theresin discharge device 50000 is moved in the direction of arrow 5 d andafter the resin is discharged so as to contact the initial point of thelight reflecting resin 5020 indicated by arrow 5 a, discharging of theresin is interrupted. With this, the light reflecting resin surroundingthe light emitting devices can be formed continuously. In addition, inFIG. 14, the light reflecting resin is disposed as an approximatelysquare frame, but it is not limited to such a shape, and various shapessuch as a circular shape, an oval shape, a polygonal shape can beemployed.

2-2-3. Alternative Method of Second Step 2

FIG. 15 is a figure illustrating an alternative method of second step.

As shown in FIG. 15, in the present method 2, the nozzle 60100 providedto the resin discharge device 60000 has a wider discharge opening thanthe nozzles used in the above-described embodiments. Moreover, theliquid resin 6020B′ is discharged while the resin discharge device 60000is at rest. That is, the resin discharge device 60000 capable of movingabove the substrate 6010 interrupts discharging in motion, and afterreaching a predetermined position, it rests to discharge the resin.

In FIG. 15, a nozzle having laterally longer opening is used and thefirst light reflecting resin 6020A and the second light reflecting resin6020B are disposed to form an approximately square frame, but theopening of the nozzle may have approximately square shape, or anL-shape, a doughnut-shape, or the like.

2-2-4. Alternative Method of Second Step 3

FIG. 17A is a figure illustrating a method of disposing a lightreflecting resin by using a mask 80000 having openings, instead of usingthe resin discharge device. FIG. 17B is a sectional view showing themask 80000 of FIG. 17A being arranged on the substrate 8010, andillustrating a state in which a squeegee is moving to injectinglysupplying a high viscosity resin 8020A through the openings 80200(so-called printing method).

As shown in FIG. 17A, an approximately square mask 80000 having openings80200 at positions corresponding to the light reflecting resin is placedover the aggregate 8000 of the light emitting devices in which the lightemitting elements are mounted on the conductor wirings on the substrate8010.

The mask 80000 has a plurality of openings 80200, and the shape, thenumber, the arrangement, and the like are appropriately adjustedaccording to the viscosity or the like of the resin. In addition,protrusions 80100B are provided so that the light emitting elements 8040and the electrically conductive wires 8050 which are mounted on thesubstrate prior to mounting the mask are prevented from being damaged bythe mask. The protrusions 80100B are preferably provided at positionscorresponding to the dividing positions in a post-process. In addition,thin plates 80100A having a thickness smaller than the protrusions80100B are provided so that the light reflecting resin is not injectedon the light emitting elements 8004.

By using such a mask 80000 and injecting a high viscosity resin from theopenings, the light reflecting resin 80200 surrounding the lightemitting elements 8040 can be disposed.

It is sufficient that the mask has a plate-like shape and openings canbe provided at desired positions, and is preferable that the mask ismade of a material resistant to deformation. As such a material, a metalsuch as Ni or SUS, a hard resin, or the like can be used. Moreover, itis preferable that the mask has approximately the same area as that ofthe substrate with which using a device capable of fixing the substratewith a jig such as a screw, the light emitting devices can bemanufactured with good location accuracy.

In addition, the squeegee for injecting the light reflecting resin intothe openings of the mask is preferably made by using a material such asa rigid urethane and a metal, and is sufficient to have an excellentstrength for printing, and the shape of the squeegee is preferably aplate-like shape, a sword-like shape, or a bar shape.

EMBODIMENT 3

FIG. 6 is a sectional view of the light emitting device 600 obtained by,after disposing the sealing member in the third step, further, the lensmember is disposed, then divided in the fourth step.

The substrate 1010 to which the sealing member is disposed, for exampleas shown in FIG. 10E, is mounted in a metal mold capable of forming thelens portion 608 as shown in FIG. 6. A liquid resin is injected in themetal mold and hardened, then divided as a fourth step to obtain thelight emitting device 600 having a lens portion.

EXAMPLE 1

As shown in FIG. 9A, a substrate which includes an alumina ceramicshaving a plate-like shape and the conductor wirings with their surfaceAg-plated disposed thereon is prepared. Six pieces of the light emittingelements made of a nitride-based semiconductor each having sides of 500μm and 290 μm are bonded on the conductor wirings by using a eutecticbonding member made of AuSn. The light emitting elements used in thepresent example produce blue emission light with the main wavelength ofabout 450 nm, and all six of them have approximately the samewavelength.

Next, a white resin (light reflecting resin) made of a silicone resinwith titania (TiO₂) having an average diameter of 0.25 μm dispersedtherein at a weight ratio of 50 wt %, is applied to surround the sixlight emitting elements.

In this way, an aggregate of the light emitting elements with the lightreflecting resin disposed thereon, as shown in FIG. 9B, is formed. Atthis time, the line width (portions at which the longitudinal andlateral light reflecting resins are not intersect each other) of eachlight reflecting resin is approximately 600 μm at the bottom (the widestdimension in top plan view) in contact with the substrate. The lightreflecting resin is disposed so that the exposed portions (exposedregions) of the alumina ceramics substrate between the conductor wiringson which the light emitting elements are mounted and the conductorwirings to which the gold wires are directly connected are covered, andthe substrate is not disposed between the light emitting elements andthe light reflecting resin. At this time, the light reflecting resin isdisposed so as also to cover a part of the electrically conductive wirestherein.

After the light reflecting resin is heat hardened, a sealing membercomprising a different silicone resin with a YAG phosphor having anaverage diameter of 6 μm dispersed therein at a weight ratio of 50 wt %is dropwisely applied on the light emitting elements surrounded by thewhite light reflecting resin to seal them.

After the sealing member is hardened, the surface side of the sealingmember is further covered by a silicone resin having a lens shape.Thereafter, the locations indicated by arrows in FIG. 9B are dividing byway of dicing to obtain the light emitting devices with the substratehaving a size of 3.5 mm×3.5 mm according to the present invention.

For comparison, a light emitting device is formed as in Example 1,except that instead of the light reflecting resin, a light transmissiveresin in which titania is not dispersed therein is used. The measurementresults of electro-optical properties are shown below.

TABLE 1 Electric current Chromaticity Total luminous flux Example 1 350mA x = 0.329 117.7 lm y = 0.332 Comparative 350 mA x = 0.326 108.8 lmexample y = 0.337

As described above, in Example 1, the electrically conductive wires andthe exposed portions of the substrate are buried in the light reflectingresin, so that the total luminous flux is about 8% higher than that ofthe comparative example in which a light transmissive resin is used.

EXAMPLE 2

A light emitting device according to the present invention is obtainedin a same manner as in Example 1, except that after mounting the lightemitting elements 904 on the conductor wiring 903A as shown in FIG. 9A,a protective element made of Si (silicon) having sides of 240 μm ismounted on the conductor wiring 903B by using an Ag paste, and the lightreflecting resin 902 as shown in FIG. 9B is disposed to cover theprotective element. In Example 2, the conductor wiring 903B is disposedsomewhat longer (larger) to mount the protective element.

EXAMPLE 3

A single light emitting element, in which a substrate provided withgold-plated conductor wirings is used and which is made of anitride-based semiconductor with the sides of 1 mm, is bonded on a blackcolor aluminum nitrate plate by AuSn eutectic. At this time, theelectrodes of the light emitting elements are arranged to face theconductor wiring side, and bonded without using the electricallyconductive wires. The light emitting elements used here have emissionwavelength in a blue region as in Example 1.

Next, a protective element having sides of 240 μm is bonded on theconductor wiring by Ag paste and electrically connected to the conductorwiring of each electrode with the electrically conductive wires made ofgold.

Next, a white resin (light reflecting resin) made of a low viscositysilicone resin with titania having an average diameter of 0.25 μmdispersed therein at a weight ratio of 20 wt %, is applied to surroundthe light emitting elements by using a dispenser.

At this time, the light reflecting resin is disposed on all thesubstrate except the mounting surface of the light emitting elements andon all the conductor wirings. Accordingly, only the surface above thelight emitting elements is exposed.

With this arrangement, light emitted from the light emitting elementscan be extracted from the upper surface without entering the blacksubstrate.

As described above, according to an embodiment of the present invention,a light emitting device capable of effectively reflecting light from thelight emitting element and in which the light extraction efficiency isimproved can be obtained.

In a case where an electrically conductive wire is used, absorption oflight by the electrically conductive wire can be suppressed.

Moreover, according to another embodiment of the present embodiment,absorption and transmission loss of light caused by the substrateexposed from the conductor wiring can be suppressed, and the lightextraction efficiency can be improved.

Further, in a case where a protective element is used, the absorption oflight by the protective element can be suppressed.

Moreover, according to still another embodiment of the presentinvention, the members which absorb light or transmit light from thelight emitting elements are buried in the light reflecting resin so thatthe light extraction efficiency can be improved.

In the light emitting device according to the present invention, theabsorption of light is reduced and high power output can be achieved, sothat it is applicable to various indicators, a lighting apparatus, adisplay, a backlight of liquid crystal display, and further to an imagescanner device for a facsimile, a copier, a scanner etc., and aprojector or the like.

It is to be understood that although the present invention has beendescribed with regard to preferred embodiments thereof, various otherembodiments and variants may occur to those skilled in the art, whichare within the scope and spirit of the invention, and such otherembodiments and variants are intended to be covered by the followingclaims.

1. A light emitting device comprising: a substrate provided with aconductor wiring; a light emitting element mounted on the substrate; anadditional light emitting element; a light reflecting resin memberconfigured and arranged to reflect light emitted from the light emittingelement; an electrically conductive wire electrically connecting theconductor wiring and the light emitting element with at least a part ofthe electrically conductive wire being embedded in the light reflectingresin member; an additional electrically conductive wire electricallyconnecting the light emitting element and the additional light emittingelement, with the additional electrically conductive wire not being incontact with the light reflecting resin member; and a sealing memberdisposed in a region surrounded by the light reflecting resin member tocover the light emitting element.
 2. The light emitting device accordingto claim 1, wherein a top surface of the light reflecting resin memberincludes a convex curved surface.
 3. The light emitting device accordingto claim 1, wherein the substrate is made of ceramic material selectedfrom the group consisting of alumina, aluminum nitride, mullite,siliconcarbide, and silicon nitride.
 4. The light emitting deviceaccording to claim 1, wherein the substrate is made of material thatabsorbs light.
 5. The light emitting device according to claim 1,wherein the light emitting element include Zener diode.
 6. The lightemitting device according to claim 1, wherein the light reflecting resinmember has a shape including a bulging part.
 7. The light emittingdevice according to claim 1, wherein a reflectivity of the lightreflecting resin member is 70% or higher.
 8. The light emitting deviceaccording to claim 1, wherein the light reflecting resin member is madeof material selected from the group consisting of phenol resin, glassepoxy resin, BT resin, and PPA resin.
 9. The light emitting deviceaccording to claim 1, wherein the sealing member includes a colorconversion member.
 10. The light emitting device according to claim 1,wherein the substrate include an alumina ceramic having an Ag-platedsurface.
 11. The light emitting device according to claim 1, wherein thesubstrate has an exposed region on which the conductor wiring is notdisposed, and the light reflecting resin member continuously covers theat least the part of the electrically conductive wire and the exposedregion of the substrate.
 12. The light emitting device according toclaim 1, wherein the conductor wiring includes a plurality of wiringportions disposed on the substrate with the light emitting element andthe additional light emitting element being mounted on one of the wiringportions.
 13. The light emitting device according to claim 1, whereinthe sealing member is in contact with at least one of the wiringportions.
 14. The light emitting device according to claim 1, whereinthe conductor wiring is disposed between the light emitting element andthe substrate.